BOSTON, March 7 (UPI) -- Children whose mothers were vitamin D deficient during pregnancy are at nearly double the risk for developing multiple sclerosis later in life, according to a study by researchers at Harvard University.
Previous studies have linked too little of the vitamin to an increased risk of MS, and some have suggested supplements could lower the risk, but researchers said their study was the first to show prenatal vitamin D exposure can affect adults later in life.
The researchers noted their study did not show whether increasing vitamin D levels could help deflate the risk, though other studies have suggested increasing vitamin D in deficient patients may lower risk for developing MS.
Dr. Benjamin Greenberg, a researcher at the University of Texas Southwestern who was not involved with the study, wrote in a commentary published in JAMA Neurology, that although other studies have explored the association between vitamin D levels and MS, this study strongly indicates the importance of the timing of the deficiency in early life.
"The timing of vitamin D deficiency has been suggested as a critical covariate to its effect on the risk of developing MS," Greenberg wrote, adding "the potential correlation between in utero vitamin D deficiency and MS would have both basic science and clinical implications."
For the new study, published in JAMA Neurology, researchers at Harvard recruited 193 people recently diagnosed with MS before 2009, whose mothers participated in the Finnish Maternity Cohort, comparing the vitamin D levels of 176 with those of 326 mothers of children who have not been diagnosed with the degenerative condition.
Overall, vitamin D levels in mothers were somewhat insufficient, but they were better among the control group than mothers whose children went on to have MS. When comparing blood samples from both groups, the children of mothers deficient in vitamin D were 90 percent more likely to develop MS.
Although other studies have suggested vitamin D supplements could help lower risk for MS, Harvard researchers wrote theirs did not. They also wrote that further studies with larger populations should be conducted to confirm the link.